Impact of pruritus in patients undergoing hemodialysis in Italy: a patient-based survey.

BACKGROUND: Itching is an annoying symptom which afflicts patients with chronic renal failure. We aimed to assess the impact and patient's perception and experience of itching in the dialysis population in Italy. METHODS: A questionnaire was developed by the National Hemodialysis and Dialysis Association of Italy (ANED) and administered to 996 hemodialysis recipients across 153 Italian dialysis centers. The main outcomes investigated by the questionnaire were patients' satisfaction on answers regarding the nature of itching; continuing to talk about itching with the nephrologist; beliefs about resolution of itching. RESULTS: A total of 1903 patients from 153 centers responded to the questionnaire. Patients who responded had a mean age of 67.9 ± 13.8 years (63.9% male) and were stratified by itch discomfort graded as mild (35.9%), moderate (29.6%), and severe (34.4%). Severe itching disrupted patients' daily lives, strained their relationships, caused anxiety, and diminished their quality of life. Patients with severe itch were more likely to talk about it with dialysis staff and to undertake dermatological visits. However, only 18.0% of patients reporting severe itching found the clinicians' responses satisfactory, compared to 49.1% of mild itch patients. Those who continued talking to nephrologists about itching received more satisfactory response. However, 40.8% believed itching could not be alleviated and were less likely to discuss it with nephrologists. CONCLUSIONS: There is an intricate relationship between the severity of itching, patient perceptions, and healthcare communication among hemodialysis patients. A substantial proportion of patients experiencing severe itching expressed feelings of resignation, highlighting the pressing need for enhanced clinician-patient communication.

Chronic hypercalcaemia from inactivating mutations of vitamin D 24-hydroxylase (CYP24A1): implications for mineral metabolism changes in chronic renal failure.

BACKGROUND: Loss-of-function mutations of vitamin D-24 hydroxylase have recently been recognized as a cause of hypercalcaemia and nephrocalcinosis/nephrolithiasis in infants and adults. True prevalence and natural history of this condition are still to be defined. METHODS: We describe two adult patients with homozygous mutations and six related heterozygous carriers. Mineral and hormonal data in these patients were compared with that in 27 patients with stage 2-3 chronic kidney disease and 39 healthy adult kidney donors. RESULTS: Probands had recurrent nephrolithiasis, chronic hypercalcaemia with depressed parathyroid hormone (PTH) and increased 1,25(OH)(2)D levels; carriers had nephrolithiasis (two of six), hypercalciuria (two of six) and high or normal-high 1,25(OH)(2)D (four of four). Corticosteroids did not reduce plasma and urine calcium levels, but ketoconazole did, indicating that 1,25(OH)(2)D production is not maximally depressed despite coexisting hypercalcaemia, high 1,25(OH)(2)D and depressed PTH, and that 1,25(OH)(2)D degradation through vitamin D-24 hydroxylase is a regulator of plasma 1,25(OH)(2)D levels. Both probands had vascular calcifications and high bone mineral content. One developed stage 3b renal failure: in this patient 1,25(OH)(2)D decreased within normal limits as glomerular filtration rate (GFR) fell and PTH rose to high-normal values, yet hypercalcaemia persisted and the ratio of 1,25(OH)(2)D to GFR remained higher than normal for any degree of GFR. CONCLUSIONS: This natural model indicates that vitamin D-24 hydroxylase is a key physiologic regulator of calcitriol and plasma calcium levels, and that balanced reduction of 1,25(OH)(2)D and GFR is instrumental for the maintenance of physiologic calcium levels and balance in chronic kidney diseases.

A thiazide test for the diagnosis of renal tubular hypokalemic disorders.

Although the diagnosis of Gitelman syndrome (GS) and Bartter syndrome (BS) is now feasible by genetic analysis, implementation of genetic testing for these disorders is still hampered by several difficulties, including large gene dimensions, lack of hot-spot mutations, heavy workup time, and costs. This study evaluated in a cohort of patients with genetically proven GS or BS diagnostic sensibility and specificity of a diuretic test with oral hydrochlorothiazide (HCT test). Forty-one patients with GS (22 adults, aged 25 to 57; 19 children-adolescents, aged 7 to 17) and seven patients with BS (five type I, two type III) were studied; three patients with "pseudo-BS" from surreptitious diuretic intake (two patients) or vomiting (one patient) were also included. HCT test consisted of the administration of 50 mg of HCT orally (1 mg/kg in children-adolescents) and measurement of the maximal diuretic-induced increase over basal in the subsequent 3 h of chloride fractional clearance. All but three patients with GS but no patients with BS and pseudo-BS showed blunted (<2.3%) response to HCT; patients with BS and the two patients with pseudo-BS from diuretic intake had increased response to HCT. No overlap existed between patients with GS and both patients with BS and pseudo-BS. The response to HCT test is blunted in patients with GS but not in patients with BS or nongenetic hypokalemia. In patients with the highly selected phenotype of normotensive hypokalemic alkalosis, abnormal HCT test allows prediction with a very high sensitivity and specificity of the Gitelman genotype and may avoid genotyping.